In image forming apparatuses, developers are likely to scatter or fly off due to shaking or inclination during shipping or transportation of the apparatuses. After an image forming apparatus is delivered to and installed in a certain place, a serviceman or the like has to refill the image forming apparatus with initial developer. Also, when replacing old developer with new developer, a service man may collect the old developer from the developing device and refill the developing device with new developer. To facilitate the initial developer refill work, a technique for supplying initial developer from a refill port to the developing device, while keeping the developing device and the photoreceptor inside the image forming apparatus, is proposed. See, for example, JP 2005-234503 A (Patent Document 1). However, with this method, toner particles are easily scattered if the developing roller and the photoreceptor are positioned apart from each other.
Another technique is proposed to place a shutter between the developing roller and the photoreceptor to prevent scattering of toner particles. See, for example, JP 2006-084892 A (Patent Document 2). However, because the shutter is an unwanted component for image reproduction, and because replacement of the developer is not carried out very often, it is desired to eliminate such a component to simplify the structure of the developing device. Still another technique is proposed to refill the developing device with an initial developer while keeping the developing device and the photoreceptor inside the image forming apparatus in the same state as in the image reproducing operation. See, for example, JP 2009-122619 A (Patent Document 3). This method does not require an extra component, such as a shutter, unlike Patent Document 2.
However, in Patent Document 3, upon supplying the initial developer, the developing device starts operating (because the stirring/feeding screw and the developing roller are simultaneously driven), and the photoreceptor is driven when the developer is supplied to the developing roller. The reason why the photoreceptor is driven at this timing is that the photoreceptor may be damaged or scratched unless it is operated during the activation of the developing device. However, if the photoreceptor is driven without supplying toner particles to the cleaning part, the cleaning blade is likely to bend or break.
By supplying toner particles to the cleaning part, friction between the photoreceptor and the cleaning blade is reduced and bending or breakage of the cleaning blade is prevented. If there is no image reproduction or image reproduction only at a low image ratio, a dummy toner belt is generally formed on the photoreceptor for the purpose of supplying toner to the cleaning part. Patent Document 3 also employs this method, and a toner belt is formed simultaneously with driving of the photoreceptor. However, with this method, the photoreceptor is activated although the developer has not been supplied to the entire surface of the developing roller, and the toner belt cannot be formed at the full length along the longitudinal area of the photoreceptor. In this case, the photoreceptor is driven under undesirable conditions with an insufficient amount of toner being supplied to the cleaning part.
In addition, since the time for driving the photoreceptor until the supplying of the initial developer is completed becomes long, the quantity of toner to be supplied to the cleaning part increases.